This invention relates to filter assemblies.
The invention is more particularly concerned with filter assemblies that are adapted for connection to a fluid-flow line.
In many applications in medical practice, such as, in epidural anaesthesia, a filter assembly is connected in a fluid-flow line to trap unwanted material, bacteria, air bubbles and so on. The filter assembly may have a thin porous membrane or other filter element mounted in a housing intermediate its inlet and outlet.
The inlet and outlet of such previous filter assemblies are commonly both provided by Luer-tapered portions of the housing. The filter assembly is connected in a fluid-flow line by coupling the Luer portions to other suitable Luer fittings provided on the up-stream and down-stream fluid-flow lines. Such assemblies are satisfactory except for the fact that they can only be used with fluid-flow lines that are terminated by suitable coupling members. In practice, many fluid-flow lines are not provided with coupling members. It has, in the past therefore only been possible to use filter assemblies with such fluid-flow lines by providing special adaptors for coupling intermediate the filter assembly and the fluid-flow lines. Such adaptors present a disadvantage because they introduce additional possible sites for leakage, require additional time to assemble, and can increase the dead-space in the fluid lines. Any increase in the number of components required during surgery or anaesthesia is generally unwelcome.